Environmental remediation of water bodies often is an extremely expensive and time consuming process of removing contaminated sediment. Numerous problems exist with traditional techniques. Historically, a dredge or excavation approach has been used to remove all the sediment in a remediation site. Such approaches, while ultimately effective, have two main drawbacks.
First is over-removal of sediment. As well as highly contaminated sediment, relatively uncontaminated sediment will also be removed. Because the dredged or excavated sediment must all be treated as if it were contaminated, the over-removal of sediment leads to increased costs of disposal. Since sediment disposal is one of the major costs of remediation, limiting the amount of sediment removed is desirable.
Second is habitat destruction. The dredge or excavation approach is a rather inexact tool, leading to significant destruction of the physical features and natural habitat in the area that has been remediated. This is particularly true for water courses such as streams, rivers, ponds and lakes. Dredging or excavating may be compared to strip mining where entire areas are scoured bare to capture all the contaminated sediment.
While advances have been made there continues to be a need for techniques that help minimize the amount of sediment removed while being effective to remediate the contamination.